program Project1;

{$APPTYPE CONSOLE}

uses
  SysUtils;

function Factr(x : Integer) : Integer;
var
   I, Res : Integer;
begin
  Res := 1;
  if(x <> 0) then
      For I := 1 to X do
          Res := Res * I;
  Factr := Res;
end;

function CNK(N, K :Integer) : Integer;
var
  a : Integer;
begin
   a := Factr(N);
   a := round(a / Factr(K));
   a := round(a / Factr(N - K));
   CNK := a;
end;

var
  Q, A : Integer;
begin
  read(Q, A);
  write(CNK(Q, A));
  readln;
  Readln;
  Readln;

end.
